1. Field of the Invention:
The present invention relates to a structure for simultaneously achieving reinforcement of a lower portion of a center pillar as well as a cross-section of a side sill and mounting of a seat-belt retractor device (an emergency-locking seat-belt take-up device) in a motorcar.
2. Description of the Prior Art:
A seat-belt retractor device has been heretofore known, which operates in such manner that when an acceleration force exceeding a predetermined magnitude is exerted upon a vehicle body or a seat-belt is going to be pulled out quickly, the device prevents the seat-belt from being pulled out by stopping rotation of a drum around which the seat-belt is wound, thus holds a rider wearing the seat-belt and insures safety of the rider. However, if this retractor device is exposed in a car cabin, there is an inconvenience that the wall surface of the car cabin is uneven, hence beautiful appearance of the car cabin is deteriorated, and also the space of the car cabin becomes narrow.
In order to avoid this shortcoming, in the prior art, as shown in FIG. 1 (See Japanese Utility Model Publication No. 57-46) an aperture 03 was formed in an inside wall portion 02 of a side sill 01, a retractor device 04 was inserted into the side sill 01 through this opening 03, and the retractor device 04 was mounted to the inside wall portion 02 by means of bolts 05.
However, since the side sill 01 is a structural member extending in the back and forth direction of a vehicle body for bearing a vertical load and a bending moment, if the aperture 03 is opened in its inside wall portion 02, a bending rigidity and a bending strength of the side sill 01, and accordingly, of the vehicle body would be degraded, hence in order to deal with this problem it is necessary to increase a sheet thickness of the side sill 01, and increase of the weight of the vehicle body and rise of a cost are inevitable.
Especially, with regard to a front seat of a passenger car where a driver sits, since in many cases a retractor device of a seat-belt is mounted to the position at the bottom of the center piller where a bending moment is largest, the above-mentioned disadvantage is remarkable.
In order to avoid such increase of a sheet thickness of the side sill, as shown in FIG. 2, in addition to a retractor device mounting member 04, center pillar reinforcement members 06 and side sill reinforcement members 07 are necessitated, resulting in increase of a number of parts and a man-hour for assembly, and this also causes rise of a cost.